On June 25, 2020, China Energy Construction participated in the design and construction of the world’s first flexible DC power grid project-Zhangbei flexible DC power grid test demonstration project. The four-end live network was connected. New energy in Zhangbei area successfully connected to the Beijing power grid. By 2022, the Beijing Winter Olympics venue.

Zhangbei flexible DC power grid test demonstration project adopts flexible DC transmission technology to construct 4 converter stations in Zhangbei, Kangbao, Fengning and Beijing, with a rated voltage of ±500 kV, a total converter capacity of 9 million kW, and supporting construction of ±500 The kilovolt direct current transmission line is 666 kilometers. Zhangbei and Kangbao converter stations are directly connected to large-scale clean energy as the sending end, Fengning station is connected to the power grid and connected to the pumped storage as the regulating end, and Beijing station is connected to the capital load center as the receiving end.

Many affiliated companies in China can participate in the survey and design, digital technical services, construction and equipment R&D and manufacturing of the project. Among them, Zhejiang Institute is responsible for the survey and design of Zhangbei Converter Station, Southwest Institute is responsible for the survey and design of Fengning Converter Station, Central South Institute is responsible for the survey and design of Beijing Converter Station, North China Institute, Northeast Institute, Anhui Institute, Hunan Institute and Jiangsu Institute are responsible for the transmission line survey. design. Losta is responsible for engineering aerial digital technology services. Tianjin Power Construction is responsible for the construction of the first bid section of the Beijing section converter station project. Beijing Equipment Company provides equipment such as 500 kV polar line circuit breakers, and has also developed the world’s first 535 kV coupled negative voltage DC circuit breaker in cooperation with Tsinghua University.

The flexible DC power grid technology is the "golden key" to solve the problem of large-scale grid energy consumption of clean energy. It is also one of the most critical technologies for efficient energy control and efficient conversion. As a new generation of transmission technology, flexible DC transmission technology has significant advantages in new energy grid connection, asynchronous grid interconnection, and urban power supply.

The North Hebei region is a 10 million kilowatt-class wind power base under the national renewable clean energy development plan. It has abundant wind and solar resources. Its installed capacity will exceed 20 million kilowatts in 2020, but there is insufficient local consumption capacity, and there is a strong demand for large-scale delivery.

The Zhangbei Rouzhi Project connects Zhangbei New Energy Base, Fengning Energy Storage Power Supply with the Beijing Load Center. In the future, it can deliver about 14.1 billion kWh of clean energy each year, which will fully meet the total of 100 million in the 26 Winter Olympic venues in Beijing and Zhangjiakou. The annual electricity demand of kWh will help the Winter Olympics venue to achieve 100% clean energy power supply.

Annual savings of 4.9 million tons of standard coal and 12.8 million tons of carbon dioxide emissions are of great significance for promoting energy transformation and green development and serving the Beijing Low-Carbon Green Winter Olympics. It will play a leading role in science and technology in implementing China's energy transformation and green development decisions and deployment, strengthening the construction of power grids and other infrastructure networks, promoting the revolution in energy production and consumption, and building a clean, low-carbon, safe and efficient energy system.

The project is a major scientific and technological pilot demonstration project that integrates large-scale renewable energy friendly access, multiple forms of energy complementation and flexible consumption, and DC power grid construction. It is also the world’s first truly DC power grid project with network characteristics. 12 items in the world.

For traditional technology, flexible DC transmission technology has flexible operation control and high intelligence, which can improve the stability of the power system, support the access and scale delivery of new energy under the condition of "weak transmission end", and improve the reliability and flexibility of the distribution network . It has unique advantages in remote areas and offshore new energy grid connection, asynchronous grid interconnection, urban power supply and other applications, and it is the most advanced transmission technology in the world today. At the same time, the DC power grid based on flexible DC transmission technology can realize multi-power supply, multi-drop power and new energy island access. It has better economy and flexibility, and can store wind power, photovoltaics, and pumped water. It can be directly connected to the load center to form a flexible and complementary energy Internet of various forms of energy. Through multi-source access and multi-energy complementation, it can effectively suppress the volatility of new energy.

After the Zhangbei Rouzhi Project is put into operation, it can inject up to 10 billion kilowatt-hours of clean energy into the Beijing Power Grid every year, which is equivalent to 1/10 of the annual electricity consumption of the whole society of Beijing. It serves the low-carbon and green Winter Olympics for promoting energy transformation and green development. Meeting, leading scientific and technological innovation, and promoting the transformation and upgrading of the equipment manufacturing industry have significant comprehensive benefits and strategic significance. Editor/Peng Xue